Access point and terminal wireless transmission power control based on point to point parameter exchanges

ABSTRACT

A wireless access point and multiple wireless terminals exchange point-to-point transmission power control parameters. The wireless access point gathers parameters based on transmissions received from each of the wireless terminals. Each wireless terminal gathers parameters based on transmissions received from each of the other wireless terminals and from the wireless access point. In one operating mode, the parameters gathered by the wireless devices are forwarded to the wireless access point, and, based on all received and local parameters, the wireless access point adjusts its own transmission power and sends control signals to the wireless terminals directing transmission power adjustment. In another mode, all parameters are exchanged between every wireless terminal and the access point so that each can independently or cooperatively make transmission power control decisions. Transmission power control parameters include received signal strength, error rates, estimated battery life, availability of unlimited power, active versus sleep mode ratios, anticipated bandwidth utilization, coding schemes available, deterministic/non-deterministic requirements, encryption and security requirements, quality of service requirements, mobility, etc. Gathering of parameters involves both retrieval of preset parameters from memory and generating parameters based on received transmissions (including test packets).

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to wireless communication systems, andmore particularly to transmit power control of wireless communicationdevices within such wireless communication systems.

BACKGROUND OF THE INVENTION

Wireless communication systems are known to support wirelesscommunications between wireless communication devices affiliated withthe system. Such wireless communication systems range from nationaland/or international cellular telephone systems to point-to-pointin-home wireless networks. Each type of wireless communication system isconstructed, and hence operates, in accordance with one or morestandards. Such wireless communication standards include, but are notlimited to IEEE 802.11, Bluetooth, advanced mobile phone services(AMPS), digital AMPS, global system for mobile communications (GSM),code division multiple access (CDMA), wireless application protocols(WAP), local multi-point distribution services (LMDS), multi-channelmulti-point distribution systems (MMDS), and/or variations thereof.

An IEEE 802.11 compliant wireless communication system includes aplurality of client devices (e.g., laptops, personal computers, personaldigital assistants, etc., coupled to a station) that communicate over awireless link with one or more access points. The transmitting device(e.g., a client device or access point) transmits at a fixed power levelregardless of the distance between the transmitting device and atargeted device (e.g., station or access point). Typically, the closerthe transmitting device is to the targeted device, the less error therewill be in the reception of the transmitted signal. However, as isgenerally understood in the art, wireless transmissions may include someerror and still provide an accurate transmission. Thus, transmitting atpower levels that provide too few errors is energy inefficient.

As is also generally understood in the art, many wireless communicationssystems employ a carrier-sense multiple access (CSMA) protocol thatallows multiple communication devices to share the same radio spectrum.Before a wireless communication device transmits, it “listens” to thewireless link to determine if the spectrum is in use by another stationto avoid a potential data collision. At lower received power levels,this protocol can lead to a hidden terminal problem when two devices,generally spaced far apart, are both trying to communication with athird device in the middle. While the device in the middle can “hear”the two devices on the periphery, these two devices cannot hear oneanother—potentially creating data collisions with simultaneoustransmissions destined for the middle device.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of ordinary skill in the artthrough comparison of such systems with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a pictorial representation of a wireless network 10 inaccordance with an embodiment of the present invention.

FIG. 2 presents a pictorial representation of a wireless network 10 thatshows examples of client devices and various modes of connection betweenaccess points and wide area network 101 in accordance with an embodimentof the present invention.

FIG. 3 presents a block diagram representation of an access point 300that can be used in wireless network 10 in accordance with an embodimentof the present invention.

FIG. 4 presents a block diagram representation of a client device 400that can be used in wireless network 10 in accordance with an embodimentof the present invention.

FIG. 5 presents a block diagram representation of a client device 400′with optional GPS circuitry 416 and power source regulation circuitry420 in accordance with an embodiment of the present invention.

FIG. 6 presents a block diagram representation of an access point 300′with optional AP assessment application 225 in accordance with anembodiment of the present invention.

FIG. 7 presents a pictorial representation of a wireless network 10 inaccordance with an embodiment of the present invention that provides apower management application 225 in one of a plurality of terminals.

FIG. 8 presents a flowchart representation of a method that can be usedin a terminal, access point and/or an integrated circuit in accordancewith an embodiment of the present invention.

FIG. 9 presents a flowchart representation of a method that can be usedin a terminal, client device and/or an integrated circuit in accordancewith an embodiment of the present invention.

SUMMARY OF THE INVENTION

The present invention sets forth a wireless network, access point,client device, integrated circuit and methods that determinetransmission power based on received signal parameters substantially asshown in and/or described in connection with at least one of thefigures, as set forth more completely in the claims that follow.

DETAILED DESCRIPTION

FIG. 1 presents a pictorial representation of a wireless network 10 inaccordance with an embodiment of the present invention. A wirelessnetwork 10 includes an access point 110 that is coupled to wide areanetwork 101. The access point 110 manages communication flow destinedfor and originating from each of client devices 121, 123, 125 and 127over a wireless network 10. Via the access point 110, each of the clientdevices 121, 123, 125 and 127 can access service provider network 105and Internet 103 to, for example, surf web-sites, download audio and/orvideo programming, send and receive messages such as text messages,voice message and multimedia messages, access broadcast, stored orstreaming audio, video or other multimedia content, play games, send andreceive telephone calls, and perform any other activities, provideddirectly by access point 110 or indirectly through wide area network101.

The access point 110 includes a power management application 225, andeach client devices 121, 123, 125 and 127 includes a client assessmentapplication 404. The power management application 225 and the clientassessment applications 404 of each of the client devices 121, 123, 125and 127 operate to select adequate transmission power settings thatconserve battery power and limit unnecessary electromagnetic radiation.For example, as directed by a client assessment application 404, theclient device 121 assess transmissions from the access point 110 and theclient devices 123, 125 and 127. The client device 121 generatesreception characteristics based on the assessment. The client device 121also gathers local status information, anticipated bandwidth utilizationcharacteristics and mobility information, and, based thereon, generatesstatus characteristics, utilization characteristics, and mobilitycharacteristics. The client device 121 delivers the receptioncharacteristics, status characteristics, utilization characteristics andmobility characteristics to the access point 110 for use by the powermanagement application 225. According to their client assessmentapplications 404, the other of the client devices 123, 125 and 127similarly gather and deliver their local status characteristics,utilization characteristics and mobility characteristics along withreception characteristics relating to others of the client devices andthe access point 110.

The access point 110, in accordance with the power managementapplication 225, also generates reception characteristics andutilization characteristics relating to each of the client devices 121,123, 125 and 127. The power management application 225 adjusts its owntransmission power and controls the transmission power of each of theclient devices 121, 123, 125 and 127 based on: 1) the receptioncharacteristics received from each of the client devices 121, 123, 125and 127 regarding others of the client devices and the access point; 2)locally generated reception characteristics and utilizationcharacteristics regarding each of the client devices 121, 123, 125 and127; 3) status characteristics from each of the client devices 121, 123,125 and 127; 4) mobility characteristics from each of the client devices121, 123, 125 and 127; and 5) utilization characteristics generated byeach of the client devices 121, 123, 125 and 127. The access point 110achieves such control by causing the access point 110 to deliver controlinstructions to each of the client devices 121, 123, 125 and 127 via thewireless network. Each of the client devices 121, 123, 125 and 127respond to the control instructions by adjusting its transmit power.Such overall control takes advantage of particular, currentcircumstances, including current operational status, relative positionsand properties of any the network nodes (e.g., the access point 110 andthe client devices 121, 123, 125 and 127).

As used herein, “reception characteristics” includes any data, generatedbased on received wireless transmissions, that rates or can be used torate the quality, accuracy or strength of such received wirelesstransmissions. For example, reception characteristics might include anyone or more of a Received Signal Strength Indication (RSSI), bit/packeterror, current/historical error rates, multipath interferenceindications, Signal to Noise Ratio (SNR), fading indications, etc.

Status characteristics includes any data relating to an underlyingdevice's prior, current or anticipated readiness, abilities or capacityfor participating on the wireless network. Status characteristicsinclude, for example, the amount of power available, such as whetheralternating current (AC) power is available or only battery power, and,if battery power, anticipated battery life at various transmission powerlevels and at various levels of participation, etc. Statuscharacteristics also include whether a device is currently “sleeping” orinactive or in a low power idle state. It may also include historicalinformation anticipating the current status duration and anticipatedstatus characteristics changes. Status characteristics may also includestatus information relating to each underlying communication softwareapplication that runs on a client device. For example, on a singleclient device two communication applications might be present with onein an inactive state and the other actively communicating. Statuscharacteristics would identify such activity and inactivity.

Utilization characteristics include any parameter that indicates aprior, current or anticipated bandwidth requirement, usage or usagecharacteristic. Utilization characteristics might include anticipatedQoS (Quality of Service) requirements, upstream/downstream bandwidthusage, bandwidth usage characteristics, idle versus active statuscharacteristics, underlying data/media types (e.g., voice, video,images, files, database data/commands, etc.) and correspondingrequirements, etc.

Mobility characteristics include for example indications as to whetherthe underlying device is: 1) permanently stationary, e.g., a desktopclient computer, game console, television, set top box or server; 2)capable of mobility, e.g., a cell phone or mobile VoIP (Voice overInternet Protocol) phone, PDA (Personal Digital Assistant), and palm,laptop or pad computer; and 3) currently moving, e.g., any one or moreof current position and direction, velocity and accelerationinformation.

The reception characteristics can be collected by a given one of theclient devices 121, 123, 125 and 127 through a test mode and through“sniffing”. In the test mode, the access point 110 directs each of theclient devices to respond with reception characteristics in response totransmissions from the access point 110 at one or more transmissionpower levels. Also, in the test mode, the access point 110 directs oneof the client devices 121, 123, 125 and 127 to transmit at one or moreselected power levels and all others to generate and deliver receptioncharacteristics in response. The access point 110 may similarly directeach of the others of the client devices 121, 123, 125 and 127 to sendthe test transmissions and correspondingly have the others respond bygenerating reception characteristics. Testing can be conductedperiodically or whenever conditions indicate that transmission poweradjustments may be needed. Devices that are mobile may undergo testingmore often than those that are stationary. Collecting receptioncharacteristics through sniffing involves a client device listening toordinary (not test) transmissions from and to the access point 110. Theaccess point 110 may request reception characteristics based on suchsniffing or may be delivered same occasionally or periodically (e.g., assignificant changes are detected) and without request by each clientdevice. Similarly, without request, status characteristics, utilizationcharacteristics and mobility characteristics may be reported assignificant changes therein occur by a client device to the access point110.

With the locally and remotely generated reception characteristics,status characteristics, utilization characteristics and mobilitycharacteristics and with periodic updates thereto, the power managementapplication 225 manages not only usage of the wireless network but alsomanages all underlying transmission power. For example, the clientdevice 123 generates reception characteristics from transmissionsbetween the client device 121 and the access point 110. In this example,the client device 123 is not capable of detecting transmissions from theclient devices 125 and 127, but does receive and generate receptioncharacteristics for transmissions from the access point 110 destined forthe client devices 125 and 127. The client device 123 delivers thereception characteristics generated to the access point 110. The clientdevice 123, a stationary desktop computer, has access to AC power, andhas a full-duplex, video streaming application running in an activecommunication state which requires significant bandwidth and QoS. Theclient device 123 communicates such corresponding statuscharacteristics, utilization characteristics and mobilitycharacteristics to the access point 110. The client device 125, abattery powered device with significant remaining battery life, isoperating with little communication traffic either direction. The clientdevice 125 generates reception characteristics for all communicationexchanges. The client devices 121 and 127, portable communicationdevices with minimal power resources, both have one or morecommunication applications active that require light but continuousbandwidth demands. Both also generate reception characteristicsregarding communication flowing in all directions. Such receptioncharacteristics and underlying status characteristics, utilizationcharacteristics and mobility characteristics are communicated to theaccess point 110. The power management application 225 of the accesspoint 110 considers all such received communications, and, for example,may direct the client device 123 to operate at full transmission powerand with protocol supported QoS and priority. At full transmissionpower, all of the other client devices should receive the transmissionsand attempt to avoid simultaneous, interfering transmissions. Similarly,the power management application 225 may reserve minimal, ongoing andcontention bandwidth for both the client devices 121 and 127, and directeach to transmit as a power level strong enough: 1) for the other of theclient devices 121 and 127 to detect; and 2) to support reliablecommunication to the access point 110. The power management application225 might direct the client device 125 to enter a sleep mode withtransmissions only as necessary and at a transmission power level onlystrong enough to support reliable reception by the access point 110. Forcommunications from the access point 110 to the client devices 121, 123,125 and 127, the power management application 225 may direct the use ofone transmission power level or the use of pluralities of power levels,e.g., corresponding to power levels tailored for communications to eachone or a subgroup of the client devices 121, 123, 125 and 127.

By way of further examples, the client devices 121 and 127 may eachadequately receive transmissions from the access point 110. However, ananalysis of their reception characteristics by access point 110 mayreveal that client device 127 cannot detect transmissions from clientdevice 121 and vice versa. In this scenario, the access point 110 maychoose to boost the transmission power of one or both of the clientdevices 121 and 127 to avoid potential hidden terminal problems thatcould occur when client device 121 and 127 attempt to transmit to accesspoint 10. An analysis of reception characteristics and statuscharacteristics by access point 110 may also reveal that the clientdevice 123 is easily detected by each of the other devices and that itis running low on battery power. In response, the access point 110 canselect a reduced transmission power level for the client device 123 thatextends its battery life. An analysis of reception characteristics andmobility characteristics by access point 110 may reveal that the clientdevice 125 is highly mobile. Rather than relying solely on receptioncharacteristics, the access point 110 selects a transmission power levelfor the client device 125 that takes into consideration its possiblemovement about the transmission range of the wireless network 10.

It should be noted that these examples are merely illustrative of themany functions and features presented in the various embodiments of thepresent invention set forth more fully in conjunction with thedescription and claims that follow.

FIG. 2 presents a pictorial representation of a wireless network 10 thatshows examples of client devices and various modes of connection betweenaccess points and wide area network 101 in accordance with an embodimentof the present invention. Wide area network 101 includes wired datanetworks 230 such as a cable, fiber, or other wired or hybrid networkfor providing access, such as narrowband, broadband or enhancedbroadband access to content that is local to wired data network 230 oris otherwise accessed through Internet backbone 217. In particular,examples of wired data networks 230 include a public switched telephonenetwork (PSTN), cable television network or private network thatprovides traditional plain old telephone service, narrowband dataservice, broadband data service, voice over internet protocol (IP)telephony service, broadcast cable television service, video on demandservice, IP television service, and/or other services.

Wide area network 101 further includes a terrestrial wireless datanetwork 232 that includes a cellular telephone network, personalcommunications service (PCS), general packet radio service (GPRS),global system for mobile communications (GSM), or integrated digitalenhanced network (iDEN). These networks are capable of accessing wireddata networks 230 through internet backbone 217 and for providing themany of the services discussed in conjunction wired data networks 230 inaccordance with international wireless communications standards such as2G, 2.5G and 3G.

Wide area network 101 also includes satellite data network 234 forproviding access to services such as satellite video services, satelliteradio service, satellite telephone service and satellite data service.In addition, wide area network 101 includes other wireless data networks236 such as a WiMAX network, ultra wideband network, edge network,Universal Mobile Telecommunication System, etc., for providing analternate medium for accessing any of the services previously described.

Access points 211-213 provide access to WAN 101 through a wiredconnection to wired data networks 230. In addition, access point 213 iscapable of providing access to wide area network 101 through wirelessdata networks 236. Set top box (STB) 214 includes the functionality ofaccess points 211, 212, and/or 213 while further including optionalaccess to terrestrial wireless data network 232, and satellite datanetwork 234. In particular, STB 214 optionally includes additionalfunctions and features directed toward the selection and processing ofvideo content such as satellite, cable or IP video content. While theterm “access point” and “set top box” have been used separately in thecontext of this discussion, the term “access point” shall include boththe functionality and structure associated with a set top box, includingbut not limited to, STB 214.

A plurality of client devices are shown that include personal computers(PC) 203 and 206, wireless telephones 204 and 207, television (TV) 205,and wireless headphones 208. These client devices are merely examples ofthe wide range of client devices that can send data to and receive datafrom access points 211-213 and STB 214. While each of these clientdevices are shown pictorially as having integrated transceiver circuitryfor accessing a corresponding access point, an separate wirelessinterface device may likewise be coupled to the client module via a portsuch as a Universal Serial Bus (USB) port, Personal Computer Memory CardInternational Association (PCMCIA) Institute of Electrical andElectronics Engineers (IEEE) 488 parallel port, IEEE 1394 (Firewire)port, Infrared Data Association (IrDA) port, etc.

Access points 211-213 and STB 214 include a power management application225 and personal computers (PC) 203 and 206, wireless telephones 204 and207, television (TV) 205, and wireless headphones 208, include clientassessment application 404 that allow these devices to implement thepower management method and structure in accordance with an embodimentof the present invention. Further discussion of these wireless networks,access points, client devices, including methods for use therewith willbe set forth in association with FIGS. 3-9 and the appended claims.

FIG. 3 presents a block diagram representation of an access point 300that can be used in wireless network 10 in accordance with an embodimentof the present invention. In particular, access point 300, such asaccess point 110, 211-213, STB 214, is presented. Access point 300includes a network interface 308 for communicating with at least onewide area network 101. While a single connection is shown, in anembodiment of access point 300, such as access point 213 and/or STB 214,network interface 308 provides a plurality of interfaces for coupling tomultiple networks of wide area network 101, such as the various networksshown in association with FIG. 2.

Access point 300 further includes access point transceiver circuitry302, operatively coupled to the network interface 308, that transmitsand receives data over a wireless link 310, to and from a plurality ofclient devices, such as client devices 121, 123, 125, 127, PCs 203 and206, wireless phones 204 and 207, TV 205 and wireless headphones 208.Access point 300 also includes memory circuitry 306, and processingcircuitry 304 that implements power management application 225. Theprocessing circuitry 304 may be a single processing device or aplurality of processing devices. Such a processing device may be, forexample, any one or more of a microprocessor, microcontroller, digitalsignal processor, field programmable gate array, programmable logicdevice, logic circuitry, state machine, analog circuitry, digitalcircuitry, and/or any device that manipulates signals (analog and/ordigital) based on operational instructions. The memory circuitry 306 maybe a single memory device or a plurality of memory devices. Such amemory device may be read-only memory, random access memory, volatilememory, non-volatile memory, flash memory, static memory, dynamicmemory, optical or magnetic storage, and/or any device that storesdigital information. Note that when the processing circuitry 304implements one or more of its functions via a state machine, logiccircuitry, analog circuitry, and/or digital circuitry, the memorystoring the corresponding operational instructions may be embedded inthe circuitry comprising the state machine, logic circuit, analogcircuit, and/or digital circuit.

In an embodiment of the present invention, wireless link 310 is awireless link of a wireless network, such as wireless network 10, thatincludes a wireless link conforming to at least one industry standardcommunication protocol such as 802.11, 802.16, 802.15, Bluetooth,Advanced Mobile Phone Services (AMPS), Global System for MobileCommunication (GSM), and a General Packet Radio Service (GPRS). Otherprotocols, either standard or proprietary, may likewise be implementedwithin the scope of the present invention.

In operation, the power management application 225 receives receptioncharacteristics, status characteristics, mobility characteristics andutilization characteristics from at least one of the plurality of clientdevices. The reception characteristics includes, for example, point topoint reception parameters such as the strength of signals received byat least one of the plurality of client devices from other devices overthe wireless link. Based on at least some of the receptioncharacteristics, status characteristics, mobility characteristics andutilization characteristics, the power management application 225selects transmission power levels for itself and for each of theplurality of client devices, and transmits corresponding control signalsto the plurality of client devices, directing transmission poweradjustment to the selected power levels. Further details, includingseveral optional features of power management application 225 arepresented in association with FIG. 6.

Network interface 300 and selected functions of AP transceiver circuitry302 can be implemented in hardware, firmware or software. Otherfunctions of transceiver circuitry 302 are implemented in analog RF(Radio Frequency) circuitry as will be understood by one skilled in theart when presented the disclosure herein. When implemented in software,the operational instructions used to implement the functions andfeatures of these devices can also be implemented on processingcircuitry 304 and stored in memory circuitry 306.

In operation, access point 300 communicates with each client device in apoint-to-point manner. To transmit data, access point 300 generates adata packet that is formatted based the protocol of wireless link 310.In particular, network interface 308 produces data payloads based ondata received from wide area network 101. Other control information anddata including the selected power levels destined for the client devicesof wireless link 310 are derived from power the management application225 of the processing circuitry 304.

AP transceiver circuitry 302 modulates the data, up-converts themodulated data to produce an RF signal of the wireless link 310. In anembodiment of the present invention, the AP transceiver circuitry 302transmits at one of a plurality of power levels, as determined by powermanagement application 225. As one of average skill in the art willappreciate, if the access point 300 operates based on a carrier sensemultiple access with collision avoidance (CSMA/CA), when access point300 transmits data, each client device in communication with wirelesslink 310 will receive the RF signal, but only the client that isaddressed, i.e., a target client device, will process the RF signal torecapture the packet.

AP transceiver circuitry 302 is further operable to receive signals fromthe plurality of client devices over wireless link 310. In thisinstance, transceiver circuitry 302 receives an RF signal, down-convertsthe RF signal to a base-band signal and demodulates the base-band signalto recapture a packet of data. In particular, data payloads destined forwide area network 101 are provided to network interface 308 to beformatted in accordance with the protocol used by wide area network 101.Other control information and data including the selected receptioncharacteristics received from the client devices of wireless link 310are provided to power management application 225 of processing circuitry304.

FIG. 4 presents a block diagram representation of a client device 400that can be used in wireless network 10 in accordance with an embodimentof the present invention. A client device 400 is presented, such asclient devices 121, 123, 125, 127, PCs 203 and 206, wireless phones 204and 207, TV 205 and wireless headphones 208. In particular, clientdevice 400 includes a client transceiver circuitry 402 that transmitsand receives data over wireless link 310, that operates in a similarfashion to access point transceiver circuitry 402. However, clienttransceiver circuitry 402 is operable to transmit at a selected powerlevel, received from access point 300.

Client device 400 includes a memory circuitry 408, and processingcircuitry 406 that implements client assessment application 404 andclient application 410. The processing circuitry 406 may be a singleprocessing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, microcontroller, digitalsignal processor, field programmable gate array, programmable logicdevice, logic circuitry, state machine, analog circuitry, digitalcircuitry, and/or any device that manipulates signals (analog and/ordigital) based on operational instructions. The memory circuitry 408 maybe a single memory device or a plurality of memory devices. Such amemory device may be read-only memory, random access memory, volatilememory, non-volatile memory, flash memory, static memory, dynamicmemory, and/or any device that stores digital information. Note thatwhen the processing circuitry 406 implements one or more of itsfunctions via a state machine, logic circuitry, analog circuitry, and/ordigital circuitry, the memory storing the corresponding operationalinstruction will be embedded in the circuitry comprising the statemachine, logic circuit, analog circuit, and/or digital circuit.

Further, client device 400 includes a client assessment application 404,operably coupled to the client transceiver circuitry 402, that assessessignals received from other devices, including other client devices,over the wireless link 310. In response, client assessment application404 generates reception characteristics and transmits the receptioncharacteristics over the wireless link to access point 300.

In operation, the client assessment application 404 includes operationalinstructions that cause processing circuitry 406 to transfer data andsignals to and from client transceiver circuitry 402; to assess signals438 received from other devices, including other client devices, overthe wireless link; and to generate reception characteristics 436. In onemode of operation, client assessment application calculates a measure ofsignal strength, such as RSSI for each of the other devices and formatsthis information as reception characteristics 436 for transmission topower management application 225. Further details, including severaloptional features of client assessment application 404 are presented inassociation with FIG. 5.

Client application 410 includes the prime functions of the deviceitself, (e.g. a television, telephones, personal computer, headphones,etc.) Selected data packets transmitted to and wide area networkoriginate 101 from data received from client application 410. Inaddition, data packets received from wide area network 101 are passed toclient application 410.

Selected functions of client transceiver circuitry 402 can beimplemented in hardware, firmware or software. Other functions of clienttransceiver circuitry 402 are implemented in analog RF circuitry as willbe understood by one skilled in the art when presented the disclosureherein. When implemented in software, the operation instructions used toimplement the functions and features of these devices can be implementedon processing circuitry 406 and stored in memory circuitry 408.

In an embodiment of the present invention, one or more components ofclient transceiver circuitry 402, processing circuitry 406 and memorycircuitry 408 are implemented on an integrated circuit.

FIG. 5 presents a block diagram representation of a client device 400′with optional GPS circuitry 416 and power source regulation circuitry420 in accordance with an embodiment of the present invention. Clientdevice 400′ can be used in place of client device 400 in any of theapplications disclosed herein. In particular, a client assessmentapplication 404 includes operational instructions that cause processingcircuitry 406 to support the power management application 225 of theaccess point 110. In particular, the client assessment application 404is operably coupled to power source regulation circuitry 420 to monitorthe charging of optional battery pack 422, monitor the charge used bybattery pack 422, to determine the remaining charge on battery pack 422and whether the optional external power source 424 is currentlyconnected.

The client assessment application 404 includes operational instructionsthat cause processing circuitry 406 to generate battery life data 432and transmit such status characteristics over the wireless link 310 viaclient transceiver circuitry 402. In one mode of operation, clientassessment application 404 generates and transmits further statuscharacteristics such as estimated remaining battery life. For instance,battery life data 432 can indicate the client device 400′ is coupled toexternal power source 424, an estimated battery life for one or moreselected power levels, an estimated battery life for one or more codingschemes, an estimated battery life battery life for one or more possibledata rates, an estimated battery life based on an estimated channelusage, an estimated battery life battery life based on an estimate ofrequired deterministic bandwidth, and an estimated battery life based onan estimate of non-deterministic bandwidth, or other estimates ofbattery life based on further operational parameters of client device400′. Also as mentioned previously, other types of statuscharacteristics can be generated pursuant to the client assessmentapplication 404 and communicated to the power management applicationrunning on the access point device 110.

Utilization characteristics can be similarly collected and communicated.For example, utilization characteristics may be retrieved directly fromthe current client application(s) or from the memory 408. Utilizationcharacteristics retrieved from the memory may have originated, forexample, based on: 1) prior interaction with or monitoring of the clientapplication 410; 2) user input; and 3) preset values.

The client assessment application 404 also causes the processingcircuitry 406 to generate and transmit mobility characteristics 434 overthe wireless link 434 via the client transceiver circuitry 402. GPSmodule 416 provides geographical data 418 such as GPS coordinates,scalar and/or vector velocities, accelerations, etc. In addition to suchgeographical coordinate data 418, mobility module can generate mobilitycharacteristics 434 that includes a mobility factor indicative ofwhether the client device is in a stationary condition, the clientdevice is in a low mobility condition such as a laptop computer thatshifts slightly on a table in a coffee shop, or whether the clientdevice is in a high mobility condition, such as in a car or other mobileenvironment. This additional mobility characteristics 434 can beassociated with a type of a device, e.g. a laptop computer may have alow mobility rating, a wireless transceiver circuitry mounted in avehicle may have a medium mobility rating, a desktop computer may have astationary mobility rating, etc. Further the mobility factor can be userselected based on the particular conditions. In addition, the mobilityfactor can be derived based on assessing a scalar or vector velocityfrom GPS module 416 and/or changes in geographical coordinate data 418over time, and comparing the velocity to one of a plurality of mobilitythresholds.

When generated and transmitted to power management application 225,battery life data 432 and mobility characteristics 434 can further beused by power management application 225 for determining a selectedpower level for client device 400′ and for other client devices ofwireless link 310.

FIG. 6 presents a block diagram representation of an access point 300′with optional AP assessment application 225 in accordance with anembodiment of the present invention. An access point 300′ is presentedthat includes many common elements of access point 300, referred to bycommon reference numerals. In addition, access point 300′ includes an APassessment application 226 that includes operational instructions, thatcause processing circuitry 304 to assess signals 438 received from theplurality of client devices, such as client device 400, over thewireless link 310. The assessed strength of signals 438 can also be usedby power management application 225 to determine the selected powerlevel the plurality of client devices of wireless link 310. Access point300′ may be used in any of the applications discussed in conjunctionwith access point 300.

In particular, access point assessment application 226 assesses signals438 received from the plurality of client devices based upon a signalstrength criteria such as RSSI, a signal to noise ratio (SNR), a noiseparameter, or an amount of bit errors, and a bit error rate (BER) ofdata received from the particular client device.

In a test mode of operation, the access point assessment application 226is operable to generate a test packet such as an echo packet that istransmitted to the client device where a reply packet is transmitted andreceived back by access point 300. The number of bit errors or the BERfor this particular packet can be calculated by comparing the receiveddata to the data that was transmitted. All other client devices that donot participate in the exchange, listen and generate receptioncharacteristics for the access point assessment application 226.

In a further “sniffing” mode of operation, the access point assessmentapplication 226 receives reception characteristics generated by thevarious client devices based on normal, ongoing packets exchanges withthe access point. For example, reception characteristics might comprisean error detecting code such as a linear block code, convolutional codeor error correcting code can be used to determine the number of biterrors in the received data, within the coding limit of the particularcode use. For instance, a (24,12) Golay code with optional CRC bit coulddetect up to 4 errors in a 24 bit coded word before the coding limit wasreached.

The power management application 225 assesses the received receptioncharacteristics 436, mobility characteristics 434, and battery life data432. Optional assessed strength of signals are received from accesspoint assessment application 226. Although not shown, other types ofstatus characteristics and utilization characteristics are also receivedand assessed by the power management application 225.

The power management application 225 implements a plurality of powermanagement rules, based on the reception characteristics 436 (includingthe assessed strength of signals), the mobility characteristics 434,utilization characteristics, battery life data 432 and other statuscharacteristics. The power management rules generate a selected powerlevel 462 to be used by one, all or a group of ones of a plurality ofclient devices, such as client device 400. Upon receiving acorresponding control instruction from the power management application225, any such client device responds adjusting the transmission power tothat selected.

For example, the power level generation module can, through operation ofthe power management rules, determine which of the client devices 400are not being heard by other client devices. In response, power levelgeneration module can establish a selected power level 462 for suchclient devices 400 to optionally boost the transmission power so thatthey will be heard by some or all of the remaining client devices. Inaddition, power level generation module can reduce the power generatedby a client device 400 that is generating a stronger than necessarysignal for being heard by the remaining client devices.

In an embodiment of the present invention, one or more components ofnetwork interface 300, access point transceiver circuitry 302, memorycircuitry 306 and processing circuitry 304 are implemented on anintegrated circuit.

FIG. 7 presents a pictorial representation of a wireless network 10 inaccordance with an embodiment of the present invention that provides apower management application 225 in one of a plurality of terminals. Awireless network 10 includes terminals 400, 401 and 402 that are eachcapable of sending and receiving data from the other terminals over awireless link.

Terminal 400 includes a power management application 225 and terminals400 and 402 include a client assessment application 404 that allows theselection of transmit power levels to promote effective communication,while reducing the power consumption of terminals. Each of the terminals400, 401 and 402 are operable to assess the signals received from otherdevices over the wireless link. Terminals 401 and 402 generate data suchas reception characteristics based on the assessed signals, battery lifedata based on estimates of power consumption, and mobilitycharacteristics based indicating how likely the signal strengths for aparticular terminal may change due to movement.

Terminals 401 and 402 transmit these data over the wireless link toterminal 400. Terminal 400, determines a selected power level for eachother terminal, based on the data that it receives for each device, andtransmits the selected power levels back to each corresponding device.The terminals 401 and 402 can then transmit at a power level that takesadvantage of their particular circumstances, including their status inthe overall wireless network 10, and based on the positions andproperties of the other terminals that are present.

In operation, terminal 400, while not performing the specific functionsof an access point, is capable of performing other features andfunctions of either access point 300 or access point 300′ discussedherein. In addition, terminals 401, while not necessarily performing thefunctions of a client application, are capable of performing otherfeatures and functions of either client device 400 or client device 400′discussed herein.

In another mode, all parameters are exchanged between every wirelessterminal and the access point so that each can independently orcooperatively make transmission power control decisions.

FIG. 8 presents a flowchart representation of a method that can be usedin a terminal, access point and/or an integrated circuit in accordancewith an embodiment of the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionspresented in association with FIGS. 1-7. In step 500, receptioncharacteristics, mobility characteristics, utilization characteristics,and status characteristics are received from one or more client devicesover a wireless link. In step 502, the signals received from one or moreclient devices over the wireless link are assessed and local receptioncharacteristics is generated. Such signals are either test signals orpart of ongoing communication exchanges. In step 504, transmission powerlevels are determined for each of the client devices and for local usebased on any part or all of the locally generated receptioncharacteristics and the received mobility, reception, utilization, andstatus characteristics. In step 506, the local transmission power isadjusted, if needed, and commands requesting transmission poweradjustments are sent to each of the client devices as needed. Thismethod is well suited for being implemented as operational instructionsthat are stored in a memory such as memory circuitry 306 and implementedusing processing circuitry such as processing circuitry 304.

For example, the status characteristics related to battery life mightindicate one or more of the following: whether the client device iscoupled to an external power source; the battery life for at least oneselected power level; the battery life for at least one coding scheme;the battery life for at least one data rate; the battery life based onan estimated channel usage; the battery life based on an estimate ofrequired deterministic bandwidth; and the battery life based on anestimate of non-deterministic bandwidth. The mobility characteristicsmight indicate, for example, one or more of the following: the clientdevice is in a stationary condition; the client device is in a lowmobility condition; the client device is in a high mobility condition;and a geographical coordinate of the client device.

The reception characteristics such as the assessment signal strengthmight include, for example, one or more of: a received signal strengthindicator (RSSI); a signal to noise ratio; a noise parameter; an amountof bit errors; and a bit error rate (BER). In one mode of operation, atest packet such as an echo packet is transmitted to the client devicewhere a reply packet is transmitted and received back. The number of biterrors or the BER for this particular packet can be calculated bycomparing the received data to the data that was transmitted.

In further mode of operation, received data is assessed based on thepayload of normal packets that are received. For instance, an errordetecting code such as a linear block code, convolutional code or errorcorrecting code can be used to determine the number of bit errors in thereceived data, within the coding limit of the particular code use. Forinstance, a (24,12) Golay code with optional CRC bit could detect up to4 errors in a 24 bit coded word before the coding limit was reached.

In one mode of operation, step 504 implements a plurality of powermanagement rules, based on the reception characteristics, and optionallythe mobility characteristics, battery life data and the assessedstrength of signals. These power management rules generate a selectedpower level for a plurality of client devices, that are equipped toreceive a selected power level and to set the selected power levelaccordingly. The selected power levels are transmitted to thecorresponding client devices. The selected power level for each clientdevice can be a discrete variable that takes on one of a finite numberof values.

For example, through operation of the power management rules, the methodcan determine which of the client devices are not being heard by otherclient devices. In response, a selected power level can be establishedfor such client devices to optionally boost the transmission power sothat they will be heard by some or all of the remaining client devices.In addition, power management rules can reduce the power generated by aclient device that is generating a stronger than necessary signal forbeing heard by the remaining client devices.

In a further example, an analysis of reception characteristics andbattery life data may reveal that a client device is easily detected byeach of the other devices and that it is running low on battery power.In response, a reduced power level can be selected for that device toextend its battery life.

In another example, an analysis of reception characteristics andmobility characteristics may reveal that a client device is highlymobile. Rather than relying solely on reception characteristics, thepower management rules select a power level for this client device thattakes into consideration its possible movement.

FIG. 9 presents a flowchart representation of a method that can be usedin a terminal, client device and/or an integrated circuit in accordancewith an embodiment of the present invention. In particular, a method ispresented for use in conjunction with one or more features and functionspresented in association with FIGS. 1-8. In step 600, signals receivedfrom other devices over a wireless link by a client device are gatheredand assessed along with battery status, device operating status, clientapplication status and anticipated communication requirements andmobility information. In step 602, based on such gathering andassessment, reception, status, utilization and mobility characteristicsare generated. In step 604, such generated characteristics aretransmitted over the wireless link. In step 606, in response to thetransmission in step 604, a command requesting a transmission powerlevel adjustment is received over the wireless link. In step 608, datais transmitted over the wireless link in accordance with the request atthe selected power level. This method is well suited for beingimplemented as operational instructions that are stored in a memory suchas memory circuitry 408 and implemented using processing circuitry suchas processing circuitry 406.

For example, the status characteristics such as battery life data canindicate one or more of the following: whether a device such as a clientdevice is coupled to an external power source, the battery life for atleast one selected power level, the battery life for at least one codingscheme, the battery life for at least one data rate, the battery lifebased on an estimated channel usage, the battery life based on anestimate of required deterministic bandwidth, and the battery life basedon an estimate of non-deterministic bandwidth. The mobilitycharacteristics can indicates one or more of the following: the clientdevice is in a stationary condition, the client device is in a lowmobility condition, the client device is in a high mobility condition,and a geographical coordinate of the client device.

The assessment signal strength can include one or more of: a receivedsignal strength indicator (RSSI), a signal to noise ratio, a noiseparameter, an amount of bit errors, and a bit error rate (BER). In onemode of operation, a test packet such as an echo packet is transmittedto the client device where a reply packet is transmitted and receivedback. The number of bit errors or the BER for this particular packet canbe calculated by comparing the received data to the data that wastransmitted.

In further mode of operation, received data is assessed based on thepayload of normal packets that are received. For instance, an errordetecting code such as a linear block code, convolutional code or errorcorrecting code can be used to determine the number of bit errors in thereceived data, within the coding limit of the particular code use. Forinstance, a (24,12) Golay code with optional CRC bit could detect up to4 errors in a 24 bit coded word before the coding limit was reached.

In one mode of operation, a device, such as a client device, terminal oraccess point, implements a plurality power management rules, based onthe reception characteristics, and optionally the mobilitycharacteristics, battery life data and the assessed strength of signals.These power management rules generate a selected power level for aplurality of client devices, that are equipped to receive a selectedpower level and to set the selected power level accordingly. Theselected power levels are transmitted to the corresponding clientdevices. The selected power level for each client device can be adiscrete variable that takes on one of a finite number of values.

For example, through operation of the power management rules, the methodcan determine which of the client devices are not being heard by otherclient devices. In response, a selected power level can be establishedfor such client devices to optionally boost the transmission power sothat they will be heard by some or all of the remaining client devices.In addition, power management rules can reduce the power generated by aclient device that is generating a stronger than necessary signal forbeing heard by the remaining client devices.

In a further example, an analysis of reception characteristics andbattery life data may reveal that a client device is easily detected byeach of the other devices and that it is running low on battery power.In response, a reduced power level can be selected for that device toextend its battery life.

In another example, an analysis of reception characteristics andmobility characteristics may reveal that a client device is highlymobile. Rather than relying solely on reception characteristics, thepower management rules select a power level for this client device thattakes into consideration its possible movement.

As one of ordinary skill in the art will appreciate, the term“substantially” or “approximately”, as may be used herein, provides anindustry-accepted tolerance to its corresponding term and/or relativitybetween items. Such an industry-accepted tolerance ranges from less thanone percent to twenty percent and corresponds to, but is not limited to,component values, integrated circuit process variations, temperaturevariations, rise and fall times, and/or thermal noise. Such relativitybetween items ranges from a difference of a few percent to magnitudedifferences. As one of ordinary skill in the art will furtherappreciate, the term “operably coupled”, as may be used herein, includesdirect coupling and indirect coupling via another component, element,circuit, or module where, for indirect coupling, the interveningcomponent, element, circuit, or module does not modify the informationof a signal but may adjust its current level, voltage level, and/orpower level. As one of ordinary skill in the art will also appreciate,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two elementsin the same manner as “operably coupled”. As one of ordinary skill inthe art will further appreciate, the term “compares favorably”, as maybe used herein, indicates that a comparison between two or moreelements, items, signals, etc., provides a desired relationship. Forexample, when the desired relationship is that signal 1 has a greatermagnitude than signal 2, a favorable comparison may be achieved when themagnitude of signal 1 is greater than that of signal 2 or when themagnitude of signal 2 is less than that of signal 1.

In preferred embodiments, the various circuit components are implementedusing 0.35 micron or smaller CMOS technology. Provided however thatother circuit technologies including other transistor, diode andresistive logic, both integrated or non-integrated, may be used withinthe broad scope of the present invention. Likewise, various embodimentsdescribed herein can also be implemented as software programs running ona computer processor. It should also be noted that the softwareimplementations of the present invention can be stored on a tangiblestorage medium such as a magnetic or optical disk, read-only memory orrandom access memory and also be produced as an article of manufacture.

As the term module is used in the description of the various embodimentsof the present invention, a module includes a functional block that isimplemented in hardware, software, and/or firmware that performs one ormodule functions such as the processing of an input signal to produce anoutput signal. As used herein, a module may contain submodules thatthemselves are modules.

Thus, there has been described herein an apparatus and method, as wellas several embodiments including a preferred embodiment, forimplementing a wireless network, access point, client device, integratedcircuit. Various embodiments of the present invention herein-describedhave features that distinguish the present invention from the prior art.

It will be apparent to those skilled in the art that the disclosedinvention may be modified in numerous ways and may assume manyembodiments other than the preferred forms specifically set out anddescribed above. Accordingly, it is intended by the appended claims tocover all modifications of the invention which fall within the truespirit and scope of the invention.

1. A wireless network having a wireless link, the wireless networkcomprising: a plurality of client devices, each of the plurality ofclient devices having client transceiver circuitry that receives dataover the wireless link and that transmits data over the wireless link ata selected power level, at least a first of the plurality of clientdevices including client device processing circuitry that assessessignals received from other of the plurality of client devices over thewireless link, generates reception characteristics, and transmits thereception characteristics and mobility characteristics over the wirelesslink; an access point having a network interface, communicativelycoupled to at least one wide area network, and access point transceivercircuitry that transmits data to and receives data from the plurality ofclient devices; and the access point receives and assesses the receptioncharacteristics and the mobility characteristics, and, based on theassessment, the access point generates the selected power level for atleast a second of the plurality of client devices, and transmit theselected power level to the at least a second of the plurality of clientdevices.
 2. The wireless network of claim 1, wherein the signalsreceived from other of the plurality of client devices over the wirelesslink that are assessed by the client device processing circuitrycomprise at least a portion of an ongoing data exchange.
 3. The wirelessnetwork of claim 1, wherein the signals received from other of theplurality of client devices over the wireless link that are assessed bythe client device processing circuitry comprise at least one test signalexchange.
 4. The wireless network of claim 1, wherein the plurality ofclient devices transmit status characteristics to the access point, andthe access point assesses at least a portion of the statuscharacteristics along with at least a portion of the receptioncharacteristics and the mobility characteristics to generate theselected power level.
 5. The wireless network of claim 1, wherein theplurality of client devices transmit utilization characteristics to theaccess point, and the access point assesses at least a portion of theutilization characteristics along with at least a portion of thereception characteristics and the mobility characteristics to generatethe selected power level.
 6. An access point comprising: a networkinterface for communicating with at least one wide area network; accesspoint transceiver circuitry, operatively coupled to the networkinterface, that transmits data to and receiving data from a plurality ofclient devices over a wireless link; and processing circuitry,operatively coupled to the access point transceiver circuitry, thatincludes a power management application having operational instructionsthat cause the processing circuitry and access point transceivercircuitry to: receive reception characteristics generated by at leastone of the plurality of client devices, the reception characteristicsincluding strength of signals received by the at least one of theplurality of client devices from others of the plurality of clientdevices over the wireless link; receive battery life data generated bythe at least one of the plurality of client devices; determine at leastone selected power level based at least in part on the receptioncharacteristics and the battery life data; and transmit the at least oneselected power level to the plurality of client devices.
 7. The accesspoint of claim 6, wherein the power management application furtherincludes operational instructions that cause the processing circuitry toreceive a mobility characteristic generated by the at least one of theplurality of client devices, and determine the selected power level forthe at least one of the plurality of client devices based at least inpart on the mobility characteristic.
 8. A client device comprising:client transceiver circuitry that receives data over a wireless link,the data including a first selected transmission power level, and thattransmits data over the wireless link at the first selected transmissionpower level; and processing circuitry, communicatively coupled to theclient transceiver circuitry, that: assesses wireless transmissions at asecond selected power level from a first device to a second device overthe wireless link; generates a reception characteristic based on theassessment; and transmits the reception characteristic and over thewireless link to the second device for use in adjusting the secondselected power level and transmits a utilization characteristic to thesecond device for use in adjusting the first selected transmission powerlevel.
 9. The client device of claim 8, wherein the wirelesstransmissions assessed by the processing comprise at least a portion ofan ongoing data exchange between the first device and the second device.10. The client device of claim 8, wherein the wireless transmissionsassessed by the processing comprise at least one test transmission. 11.The client device of claim 8, wherein the processing circuitry deliversa status characteristic to the second device for use in adjusting thefirst selected transmission power level.
 12. The client device of claim8, wherein the processing circuitry delivers a mobility characteristicto the second device for use in adjusting the first selectedtransmission power level.
 13. In a communication infrastructuresupporting a client device and other devices, a method used byprocessing circuitry of an access point, the method comprising:receiving a reception characteristic from at least one of the otherdevices over a wireless link, the reception characteristic relating toat least one wireless transmission from the client device to the accesspoint over the wireless link; receiving a utilization characteristicfrom the client device over the wireless link; determining, based atleast in part on the reception characteristic and the utilizationcharacteristic received from the at least one of the other devices, thata transmission power adjustment is needed; and transmitting to theclient device a request to carry out the transmission power adjustment.14. The method of claim 13, further comprising receiving a power supplycharacteristic from the client device over the wireless link; and thedetermining that a transmission power adjustment is needed is also basedat least in part on the power supply characteristic received.
 15. Themethod of claim 13, further comprising receiving a status characteristicfrom the client device over the wireless link; and the determining thata transmission power adjustment is needed is also based at least in parton the status characteristic received.
 16. The method of claim 13,further comprising receiving a mobility characteristic from the clientdevice over the wireless link; and the determining that a transmissionpower adjustment is needed is also based at least in part on themobility characteristic received.
 17. In a communication infrastructuresupporting a client device and other devices, a method used byprocessing circuitry of an access point, the method comprising:receiving a reception characteristic from at least one of the otherdevices over a wireless link, the reception characteristic relating toat least one wireless transmission from the client device to the accesspoint over the wireless link; receiving a mobility characteristic fromthe client device over the wireless link; determining, based at least inpart on the reception characteristic and the mobility characteristicreceived from the at least one of the other devices, that a transmissionpower adjustment is needed; and transmitting to the client device arequest to carry out the transmission power adjustment.
 18. The methodof claim 17, further comprising receiving a power supply characteristicfrom the client device over the wireless link; and the determining thata transmission power adjustment is needed is also based at least in parton the power supply characteristic received.
 19. The method of claim 17,further comprising receiving a status characteristic from the clientdevice over the wireless link; and the determining that a transmissionpower adjustment is needed is also based at least in part on the statuscharacteristic received.